Souza JA, Flores AAV

Abundance and active patch selection modulate

living on sand dollars

Sand dollars function as habitat patches for many pea crab species, and behaviorally-mediated host switches may deeply alter crab metapopulation dynamics. Souza & Flores show that unlike the uniform distributions of whole-sand dollar populations, subsets of occupied patches are markedly clumped. Females likely mediate crab interactions and thus migration patterns, expelling other females and indirectly increasing the frequency of patches with a heterosexual pair. At intermediate overall crab densities, crab movements increase the chances of mating interactions (i.e. reproductive connectivity), potentially enhancing reproductive output of crab metapopulations. Individual female fitness, proxied by fecundity, remain high at intermediate crab densities, decreasing at the lowest (e.g., Allee effects) and the highest densities observed (e.g., energetic costs of intraspecific competition).

Abstract   Back to contents page   Link to full PDF